
TY  - JOUR
A1  - Burge, GL 
A1  - Collins, DJ 
A1  - Reitze, JD 
T1  - Synthesis of 3-Ethenyl-4-methylcyclohex-2-en-1-one from 4-methylanisole
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1982
VL  - 35
IS  - 9
SP  - 1913
EP  - 1925
KW  - 
UR  - https://doi.org/10.1071/CH9821913 
N2  - Epoxidation of 8-methyl-1,4-dioxaspiro[4,5]dec-7-ene (13) with peroxybenzoic acid afforded 6'-methylspiro[1,3-dioxolan-2,3'-[7]oxabicyclo[4,1,0]heptane] (12), isomerization of which with a catalytic amount of lithium perchlorate in refluxing benzene yielded 8-methyl-1,4-dioxaspiro-[4,5]decan-7-one (15). Reaction of this with vinylmagnesium bromide gave one diastereoisomer of 7-ethenyl-8&#958;-methy1-1,4-dioxaspiro[4,5]decan-7-ol (18a) or (18b). Attempts to dehydrate this alcohol resulted in either no reaction, or in formation of ketonic products including 3-ethenyl-4-methyl-cyclohex-2-en-1-one (4). Mild treatment of the hydroxy vinyl acetal (18a) or (18b) with dilute sulfuric acid in dioxan afforded crystalline 3-ethenyl-3-hydroxy-4-methylcyclohexanone (19) which when allowed to react with dilute sulfuric acid in ethanol at room temperature gave 3-ethenyl- 4-methylcyclohex-2-en-1-one (4). The crystalline dithioacetal (20), obtained from 3-ethenyl-3-hydroxy-4-methylcyclohexanone (19), gave a complex mixture of products upon attempted dehydration with thionyl chloride in pyridine. 
ER  -

